OK.
So, I'm the one who mentioned this that night. And I did use it, as well as at least one other person who used it to try and not rearend me.

I DO NOT RECOMMEND USING THIS TACTIC, except in extreme circumstances and only on VERY slippery surfaces, I.E. Ice/compacted snow or really slippery mud.

That night, I got to sliding pretty fast and right at a tree. I didn't even think about it, I just did it, and I stopped just shy of the tree. I used it later to stop after having picked up considerable speed trying to get away from an incoming FJ.

OBVIOUSLY this should only ever be done when ALL FOUR tires are locked up and NOT turning. And then you floor it, and then let off the brake, to produce initial backwards spin on the ice, thus giving uphill force on the vehicle while minimizing stress to your moving parts.

That being said, this obviously does put unwanted stress on your moving parts involved. And outside of a really slippery circumstance, should never be executed.

As far as it perpetuating the slippery surface for the later rigs coming down the hill... I doubt it, as there wasn't much snow left on the areas where I executed this move. I pretty much dug it out to the mud below.

That's just my $0.02 I know many of you will probably disagree with this, and think me foolish for using it. But, I made it out in one piece without hitting trees or other rigs. Seems legit to me. Hopefully I'll never have to use it again.
Thinking back about 7 years ago, I wish I had used this technique one rainy muddy night. Might have prevented me from hitting that oak tree at the bottom of a hill. Who's to know.

Bottom line: To each his own.

(side note) If this does get adopted for use in emergency situations, I call dibs on it. It will be know from now on as "Pulling a Shotshell."